Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

FDA Approves Four-Strain Flu Vaccine

A new nasal-spray flu vaccine approved by the U.S. Food and Drug Administration protects against four strains of common flu, adding one more barrier to infection.

Okayed for people 2 to 49 years old, the FluMist Quadrivalent vaccine from AstraZeneca guards against two strains of influenza A and two strains of influenza B, the Associate Press reported. Previous vaccines protected against two influenza A strains but only one influenza B strain.

"Illness caused by Influenza B virus affects children, particularly young and school-aged, more than any other population," Dr. Karen Midthun, director of the FDA biologics center, said in an agency news release.

Flu sickens millions of people a year. Annual deaths from flu vary widely, with FDA figures showing a low of 3,000 and a high of 49,000 over the past 30 or so years, the AP said.

The new vaccine, much like the existing FluMist vaccine, carries a weakened strain of the virus.

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Reconsider Decision Not to Publish Bird Flu Research, Experts Say

U.S. health officials have asked government biosecurity advisers to reconsider their recommendation that details of research involving the spread of so-called H5N1 bird flu be withheld from the public.

Dr. Anthony Fauci of the National Institutes of Health on Wednesday said new information has come to light, and that flu experts at the World Health Organization have also concluded that the work should be published, the Associated Press reported.

Research conducted in Wisconsin and the Netherlands recently triggered alarm when it appeared that scientists had devised a form of bird flu that spread more easily from mammal to mammal. U.S. officials, fearing a deadly flu of pandemic proportions, urged that details of the experiments be withheld from the public so they couldn't be used by bioterrorists.

But at a meeting of researchers Wednesday, Dr. Ron Fouchier, a virology professor at the Netherlands' Erasmus University, and one of the original team members, said the strain didn't spread easily after all and that people with exposure to regular flu seemed protected from serious infection.

Publishing the research would benefit the scientific community and further research into bird flu mutations, vaccines and treatment, Fouchier said.

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Feds Uncover Record-Breaking Medicare Scam

A Texas doctor allegedly recruited homeless people as fake patients in a wide-ranging, $375 million Medicare home health-care scam, the largest ever uncovered, investigators say.

Dr. Jacques Roy, 54, was arrested Wednesday and charged with falsifying hundreds of Medicare claims and taking millions of dollars for unneeded or undelivered services. He could be sent to prison for life, ABC News reported.

"According to the indictment, Dr. Roy and his co-conspirators, for years, ran a well-oiled fraudulent enterprise in the Dallas area, making millions by recruiting thousands of patients for unnecessary services, and billing Medicare for those services," said Assistant Attorney General Lanny Breuer.

The indictment alleges that Roy certified more Medicare beneficiaries for home health services and claimed more patients than any other U.S. doctor in the years 2006 to 2011, ABC said.

To obtain reimbursement from Medicare, doctors must certify that the medical services were needed and performed. Roy's operation, Medistat Group and Associates, allegedly certified false claims involving nearly 500 home health care companies in Texas. The companies were reimbursed for the bogus or unnecessary services and provided Roy with a portion of the "refund." All told, they billed Medicare for more than $350 million and Medicaid for more than $24 million, the news report said.